does anyone knowif plus plugs work and how much horse power do they give you?  

Some say yes, some say no. I think Import Tuner did a test and it did show an improvement in hp. The thing is with the pulse plugs is that they advertise that their spark plugs can generate more spark, but the spark plug itself can't produce a larger spark, unless you change the coils. I believe that it's all advertising and its a gimmick, kinda like those Tornado intake thingys, but hey if you have the money, then go for it. If not just stick with NGK or whatever brand of your choosing.